Out-of-Bounds Access Vulnerability in Linux Kernel Affecting Certificate Parsing

CVE-2026-31430

What is CVE-2026-31430?

A vulnerability has been identified in the Linux kernel, which allows an unprivileged user to trigger an out-of-bounds access when parsing certificates with empty Basic Constraints or Key Usage extensions. This occurs because the kernel reads the first byte of the extension without validating its length. By submitting a specifically crafted certificate via the keyrings API, a malicious user can exploit this flaw. This issue has been responsibly disclosed and fixed to mitigate potential exploitation.

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